build-system: Add pyproject-build-system.

This is an experimental build system based on python-build-system
that implements PEP 517-compliant builds.

* doc/guix.texi (Build Systems): Add pyproject-build-system section.
* doc/contributing.texi (Python Modules): Mention pyproject.toml and the
PYTHON-TOOLCHAIN package, as well as differences to python-build-system.
* guix/build-system/pyproject.scm,
guix/build/pyproject-build-system.scm,
gnu/packages/aux-files/python/sanity-check-next.py,
gnu/packages/python-commencement.scm: New files.
* Makefile.am (MODULES): Register the new build systems.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add python-commencement.scm.
* gnu/packages/python.scm (python-sans-pip, python-sans-pip-wrapper): New
variables.

Co-authored-by: Marius Bakke <marius@gnu.org>

1 files changed, 147 insertions, 0 deletions

diff --git a/guix/build-system/pyproject.scm b/guix/build-system/pyproject.scm
new file mode 100644
index 0000000000..1e365d4f21
--- /dev/null
+++ b/guix/build-system/pyproject.scm
@@ -0,0 +1,147 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2021 Lars-Dominik Braun <lars@6xq.net>
+;;; Copyright © 2022 Marius Bakke <marius@gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix build-system pyproject)
+  #:use-module ((gnu packages) #:select (search-auxiliary-file))
+  #:use-module (guix gexp)
+  #:use-module (guix store)
+  #:use-module (guix utils)
+  #:use-module (guix memoization)
+  #:use-module (guix gexp)
+  #:use-module (guix monads)
+  #:use-module (guix packages)
+  #:use-module (guix derivations)
+  #:use-module (guix search-paths)
+  #:use-module (guix build-system)
+  #:use-module (guix build-system gnu)
+  #:use-module (guix build-system python)
+  #:use-module (ice-9 match)
+  #:use-module (srfi srfi-1)
+  #:use-module (srfi srfi-26)
+  #:export (%pyproject-build-system-modules
+            default-python
+            pyproject-build
+            pyproject-build-system))
+
+;; Commentary:
+;;
+;; Standard build procedure for Python packages using 'pyproject.toml'.
+;; This is implemented as an extension of 'python-build-system'.
+;;
+;; Code:
+
+(define %pyproject-build-system-modules
+  ;; Build-side modules imported by default.
+  `((guix build pyproject-build-system)
+    (guix build json)
+    ,@%python-build-system-modules))
+
+(define (default-python)
+  "Return the default Python package."
+  ;; Lazily resolve the binding to avoid a circular dependency.
+  (let ((python (resolve-interface '(gnu packages python))))
+    (module-ref python 'python-toolchain)))
+
+(define sanity-check.py
+  ;; TODO: Merge with sanity-check.py in the next rebuild cycle.
+  (search-auxiliary-file "python/sanity-check-next.py"))
+
+(define* (lower name
+                #:key source inputs native-inputs outputs system target
+                (python (default-python))
+                #:allow-other-keys
+                #:rest arguments)
+  "Return a bag for NAME."
+  (define private-keywords
+    '(#:target #:python #:inputs #:native-inputs))
+
+  (and (not target)                               ;XXX: no cross-compilation
+       (bag
+         (name name)
+         (system system)
+         (host-inputs `(,@(if source
+                              `(("source" ,source))
+                              '())
+                        ,@inputs
+
+                        ;; Keep the standard inputs of 'gnu-build-system'.
+                        ,@(standard-packages)))
+         (build-inputs `(("python" ,python)
+                         ("sanity-check.py" ,(local-file sanity-check.py))
+                         ,@native-inputs))
+         (outputs (append outputs '(wheel)))
+         (build pyproject-build)
+         (arguments (strip-keyword-arguments private-keywords arguments)))))
+
+(define* (pyproject-build name inputs
+                          #:key source
+                          (tests? #t)
+                          (configure-flags ''())
+                          (build-backend #f)
+                          (test-backend #f)
+                          (test-flags #f)
+                          (phases '%standard-phases)
+                          (outputs '("out" "wheel"))
+                          (search-paths '())
+                          (system (%current-system))
+                          (guile #f)
+                          (imported-modules %pyproject-build-system-modules)
+                          (modules '((guix build pyproject-build-system)
+                                     (guix build utils))))
+  "Build SOURCE using PYTHON, and with INPUTS."
+  (define build
+    (with-imported-modules imported-modules
+      #~(begin
+          (use-modules #$@(sexp->gexp modules))
+
+          #$(with-build-variables inputs outputs
+              #~(pyproject-build
+                 #:name #$name
+                 #:source #+source
+                 #:configure-flags #$configure-flags
+                 #:system #$system
+                 #:build-backend #$build-backend
+                 #:test-backend #$test-backend
+                 #:test-flags #$test-flags
+                 #:tests? #$tests?
+                 #:phases #$(if (pair? phases)
+                                (sexp->gexp phases)
+                                phases)
+                 #:outputs %outputs
+                 #:search-paths '#$(sexp->gexp
+                                    (map search-path-specification->sexp
+                                         search-paths))
+                 #:inputs %build-inputs)))))
+
+
+  (mlet %store-monad ((guile (package->derivation (or guile (default-guile))
+                                                  system #:graft? #f)))
+    (gexp->derivation name build
+                      #:system system
+                      #:graft? #f                 ;consistent with 'gnu-build'
+                      #:target #f
+                      #:guile-for-build guile)))
+
+(define pyproject-build-system
+  (build-system
+    (name 'pyproject)
+    (description "The PEP517-compliant Python build system")
+    (lower lower)))
+
+;;; pyproject.scm ends here